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nataraj
Joined: 03 Aug 2007 Posts: 1048 Location: near Vienna, Austria
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Posted: Tue Jul 22, 2008 6:39 am Post subject: July 22 VH |
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This time, the "very hard" point comes rather early, while there are still quite a few unsolved cells around, so some searching is required.
xy-wing 29-24-49 row 2 col 8, it takes out 9 in r5c5.
Also, for those who like to exhaust all basic techniques before going "vh", there is a naked quint(?) / hidden pair in box 4 (not needed for the solution).
I also found an xyz-wing but it did not do very much (249 col 4/box 2) |
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LloydB
Joined: 09 Jul 2007 Posts: 21 Location: Skagit Co., WA USA
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Posted: Tue Jul 22, 2008 9:42 am Post subject: |
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I also found the xyz wing but it may not have been needed as I later found a 249 xy wing which didn't seem to depend on it. That cracked the puzzle. |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Tue Jul 22, 2008 12:25 pm Post subject: |
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I initially found the <249> xy-wing. Then as I was cleaning up, I saw a Type 1 UR on <46> which I took but was apparently not needed to complete the puzzle.
Ted |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Tue Jul 22, 2008 12:32 pm Post subject: Re: July 22 VH |
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nataraj wrote: |
Also, for those who like to exhaust all basic techniques before going "vh", there is a naked quint(?) / hidden pair in box 4 (not needed for the solution).
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Nataraj, it can also be viewed as a naked quad / hidden pair in column 1, which is how I found it.
Ted |
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cgordon
Joined: 04 May 2007 Posts: 769 Location: ontario, canada
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Posted: Tue Jul 22, 2008 7:18 pm Post subject: |
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I prefer ER’s and UR’s, but could only find the 249 xy wing. Seems this is all that is available at the VH stage. |
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Clement
Joined: 24 Apr 2006 Posts: 1111 Location: Dar es Salaam Tanzania
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Posted: Tue Jul 22, 2008 8:21 pm Post subject: Daily Sudoku: Tue 22 Jul-2008 VH |
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XY-Wing 249 Pivot {2,4}r2c8 with pincers 29 r2c5 and 49 r5c8 eliminating 9 in r5c5 solving the puzzle. |
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cgordon
Joined: 04 May 2007 Posts: 769 Location: ontario, canada
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Posted: Wed Jul 23, 2008 10:34 pm Post subject: |
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Quote: | there is a naked quint hidden pair in box 4 |
That ain't no quint. A quint is a five job - eg "one of five children born at the same time from the same pregnancy." A quad maybe? |
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nataraj
Joined: 03 Aug 2007 Posts: 1048 Location: near Vienna, Austria
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Posted: Thu Jul 24, 2008 6:24 am Post subject: |
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quad, quint ... hm, it probably depends on one's point of view.
In box 4 there is a hidden pair/naked quint
In col 1 there is a hidden pair / naked quad.
When I first did it I missed the box/line elimination that took out a 7 in r7c1...
And, of course the xy wing is there already ...
Code: |
+--------------------------+--------------------------+--------------------------+
| 29 5 49 | 2489 7 48 | 1 6 3 |
| 1 7 3 | 6 29 5 | 249 24 8 |
| 269 8 469 | 249 1 3 | 29 7 5 |
+--------------------------+--------------------------+--------------------------+
| 789 19 5 | 89 4 6 | 3 129 27 |
| 6789 469 2 | 3 89 1 | 5 49 467 |
| 369 13469 169 | 7 5 2 | 8 149 46 |
+--------------------------+--------------------------+--------------------------+
| 369 369 679 | 1 238 478 | 246 5 24 |
| 5 136 167 | 24 23 47 | 246 8 9 |
| 4 2 8 | 5 6 9 | 7 3 1 |
+--------------------------+--------------------------+--------------------------+
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